Abstract: Objective The interaction of mizolastine with bovine serum albumin(BSA) was investigated with quenching of BSA fluorescence by mizolastine.Methods Fluorescence spectroscopy was employed to study the Stern-Volmer quenching constants(Ksv) of BSA in the presence of mizolastine in pH 7.4 PBS.The CD and UV absorption spectra were used to investigate the effect of mizolastine on the conformation of BSA.Results The quenching constants(Ksv) and corresponding thermodynamic parameters(ΔH,ΔS and ΔG) were calculated from the spectroscopic data at different temperatures.Conclusion The Ksv suggests that the quenching of BSA fluorescence by mizolastine occurs through the static process.The ΔH,ΔS and ΔG obtained at different temperatures show that the binding of mizolastine to BSA is mainly driven by hydrophobic force.The addition of mizolastine leads to the conformational changes of BSA.

Key words: fluorescence spectroscopy, UV spectroscopy, circular dichroism(CD), mizolastine, bovine serum albumin